1. Field of the Invention
The present invention relates to a disc record sound reproducing apparatus for reproducing a sound by selecting a desired modulated groove from a plurality of modulated grooves formed in the disk record.
2. Prior Art
A prior art disk record sound reproducing apparatus for reproducing a sound by selecting a modulated groove is disclosed, for example, in Japanese Patent Laid-Open Publication No. 64-14701.
In this apparatus, a flange is formed on a periphery of a disk record having a plurality of modulated grooves, and an index portion is formed by cutting out an arbitrary point of the flange. Furthermore, a stylus force releasing operating wheel of a cylindrical shape is disposed surrounding the disk record, and at the same time, a lateral side surface of the stylus force releasing operating wheel is cut out to form an inclined surface, and the stylus force releasing operating wheel is formed with a stylus force releasing bar at a position adjacent to a sound transmitting body which is coupled to a pickup. Furthermore, a plurality of selection bars are disposed at predetermined intervals so that the selection bars are biased downwardly to come adjacent to the stylus force releasing operating wheel and the selection bars move up and down. Each of the selection bars is formed with a coupling member which is elastically deformed and rides on the flange, and is formed with a pressing portion for pressing the slant surface of the stylus force releasing operating wheel.
Accordingly, in the prior art apparatus, by advancing the selection bar by pressing it, the pressing portion of the selection bar presses the slant surface of the stylus force releasing operating wheel to rotate the operating wheel, and the stylus force releasing bar moves the sound transmitting body upwardly, thereby releasing the stylus force. At the same time, the coupling member of the selection bar rides on the flange and the stylus force released condition is maintained. When the disk record rotates and the index portion of the flange reaches the coupling member, the coupling member passes through the index portion, and the selection bar retards due to the biasing of a spring. As a result, the stylus force releasing operating wheel and the stylus force releasing bar return to the original positions, and the stylus force is applied to the disk record to reproduce a sound from the disk record.
Because the timing of releasing the stylus force is determined by a relative position between the index portion of the flange and the selection bar, one of the modulated grooves to be reproduced is decided depending on which of the selection bars is operated.
However, in the prior art apparatus described above, since the release of the stylus force and the application of the stylus force are achieved by using a plurality of movable parts such as the selection bars, stylus force releasing operating wheel, etc., a problem is involved in which the number of operating parts is increased, and thus, the high durability cannot be easily maintained. Furthermore, since the return springs and the like must be provided, to respectively return the movable parts to predetermined positions, a problem is involved in which the structure is complicated and many hours of labor are needed for the manufacturing and assembling of the parts, and the manufacturing efficiency is not satisfactory.